/Engine/Plugins/Experimental/PlanarCutPlugin/Source/PlanarCut/Public/PlanarCut.h
Recompute normals and tangents of selected geometry, optionally restricted to faces with odd or given material IDs (i.e. to target internal faces)
void RecomputeNormalsAndTangents ( bool bOnlyTangents, bool bMakeSharpEdges, float SharpAngleDegrees, [FGeometryCollection](API\Runtime\Chaos\GeometryCollection\FGeometryCollection) & Collection, const [TArrayView](API\Runtime\Core\Containers\TArrayView)< const int32 > & TransformIndices, bool bOnlyInternalSurfaces )